To satisfy the increasing demands for wireless data traffic since commercialization of 4th generation (4G) communication systems, efforts have been made to develop an improved 5th generation (5G) communication system or a pre-5G communication system. For this reason, the 5G or pre-5G communication system is referred to as a beyond-4G or post long term evolution (LTE) system.
To achieve high data rates, deployment of the 5G communication system in a millimeter wave (mmWave) band (for example, a 60-GHz band) is under consideration. For the 5G system, beamforming, massive multiple input multiple output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, analog beamforming, and large-scale antenna techniques have been discussed in order to mitigate the path loss and propagation distance of waves.
Further, for network improvement in a system, technologies such as evolved small cell, advanced small cell, cloud radio access network (RAN), ultra-dense network, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, coordinated multi-point (CoMP), and interference cancellation have been developed in the 5G system.
Besides, advanced coding modulation (ACM) techniques such as hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC), and advanced access techniques such as filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) have been developed in the 5G system.
The Internet is evolving from a human-oriented connection network in which human beings generate and consume information to the Internet of things (IoT) in which information is transmitted/received and processed between distributed elements such as things. The Internet of everything (IoE) technology may be an example in which the IoT is combined with big data processing through connectivity to a cloud server or the like.
For IoT implementation, technologies such as sensing, wired/wireless communication, network infrastructure, service interfacing, and security are required. Recently, techniques including a sensor network for interconnection between things, machine to machine (M2M) communication, and machine type communication (MTC) have been studied.
An intelligent Internet technology (IT) service of creating new values for human livings by collecting and analyzing data generated from interconnected things may be provided in an IoT environment. The IoT may find its applications in a wide range of fields including smart home, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart appliances, and state-of-the art medical service, through convergence between existing IT technologies and various industries.
In this context, many attempts have been made to apply the 5G system to the IoT. For example, 5G technologies such as sensor network, IoT, and MTC are implemented by techniques such as beamforming, multiple input multiple output (MIMO), and array antenna. The afore-described application of a cloud RAN as a big data processing technology is also an example of convergence between 5G technology and IoT.
Along with large-scale investment of service operators in VR services, it is expected that the VR services will be extended as main future-generation services. In general, VR refers to an almost-real environment or situation created by computer graphics. VR provides an interface which a human feels with his or her sense organs and tricks the human into feeling really interactive. A user may interact with VR by manipulating a device and have nearly real sensational experiences.
Augmented reality (AR), a field of VR, is a computer graphic technique which combines a real environment with a virtual object or information so that the virtual object or information may be seen as it really exists. AR which overlays a virtual object into a real world viewed by a user is also called mixed reality (MR) in the sense that a real world is combined with additional information and a virtual world in real time and viewed as one image.
Further, owing to the proliferation of mobile devices (for example, smartphones and tablet personal computers (PCs)), VR becomes more popular in various services such as education, gaming, navigation, advertisement, or blogs. As wearable devices have recently been commercialized, VR has become a more active research area.
For example, wearable devices are provided in various forms wearable and attachable on a body and clothes, such as a head-mounted type, glasses, a watch, a band, contact lenses, a ring, and clothes. As electronic devices are configured to be wearable as clothes or glasses on a user's body, the wearable devices may increase portability and accessibility.
Although VR was a non-streaming service in its early stage in which VR dedicated content is all downloaded to a VR device and then reproduced, VR has been developed to a service in which VR content is received and reproduced in real time by streaming from a server.